Repairs deprecation notice for KAS privateApi

What does this MR do?

Repairs deprecation notice for KAS privateApi

• Prior art allowed the simple fact that enabling KAS showed this warning despite the fact that the user may not have set this value
  • This is because it is the default configuration as defined in the helm chart values file for KAS as shipped by us
• To prevent confusion for the end user whom may not have set this value, simply check if the enablement of this feature is true
  • This WOULD be a signal the user is actively leveraging a deprecation and should move away

Related issues

Addresses: gitlab-com/gl-infra/delivery#19276 (closed)

Reference implementation: !2888 (merged)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com (I see CI failed on specs, but it appears unrelated to changes - especially since this is just a change to NOTES.txt.)
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.